OKC can take a swing. They have about a year before they will need to use their cap differently, which lines up well with when Simmons contract expires. They are not getting any value from Hayward, but the Nets might. They can sugar it up with a pick or something as I do feel that Golden State Warriors and Spurs could actually do well with Simmons fit wise.
OKC gains with Simmons as a playmaker that passes, which they need. He is good at their core drive and kick and back cut passes. He also covers their need for size that can't be a Centre as Chet is set on being the centre. Simmons can play point/power forward and give the size they need there for the teams with more bigger bodies and add to the rebounding they need.
In contrast though Spurs could take that ticket on his playmaking for Wemby if they don't feel they will get a good enough PG in the draft or they wish to build them slower. GSW has spacing and defs also a potential ticket taker to contend with if anyone feels he has enough chance of not being injured.
OKC really has the lowest risks to take on it with the cap space timing, and how he covers needs though